Improvement in stamping varnished surfaces



FFICE.

TEILE H. MTTLLER, OF YONKERS, NEW YORK, ASSIGNOR TO JOSEPH BECK- ENDORFER, NEW YORK CITY.

IMPROVEMENT-1N STAMPING VARNISHED SURFACES.

Specification forming part of Letters Patent No. 122,636, dated J anuary 9, 1872.

To whom it may concern:

Be it known that I, TEILE H. MtiLLER, of Yonkers, Westchestcr county, New York, have invented certain new and useful Improvements in Stamping Varnished Articles with Bronze,

of which the following is a specification:

So-called gilt-stamps have been put on leadpencils and other varnished articles up to the present time by means of leaf gold or leaf metal pressed with a heated die into the varnished surface, the superfluous parts of the metal be in g then wiped ofi, after which, if leaf metal or silver is used, the stamp is covered with a thin coat of varnish to prevent it from tarnishmg.

In the use of leafmetal two different processes are employed, both being equally tedious and both requiring skilled labor. The first method, mainly used in Europe in connection with handpresses, consists in applying a piece of leaf metal (gold, silver, or metal, the latter being a composition similar to brass or statue-bronze hammered into thin leaves) to the heated die, which is then pressed onto the pencil, the projections of the die pressing the leaf metal on the varnish, which is melted to a certaindegree, thereby causing the thin metal to adhere firmly to the varnished surface. After the die is raised the pencil is taken from the press, allowed to coola momentin order to give the varnish time to reharden, and then is wipedclean, and, if necessary, varnished, the so-called gilt finishing-coat being given, after which it is ready to be boxed. The second method, used in this country, is to cut the metal to the required size on a leather cushion, and then to apply it to the pencil by means of some sizing material, after which the pencil is stamped with a hot die, as above described. Both of these processes are tedious, expensive, and faulty. The first requires three skilled operatives-one Stamper, one to cut the metal and lay it on the die, and one to wipe and clean the pen oil or other stamped article, the die becomes quickly clogged or stuffed --that is, the indentations of the die become soon filled with amixture of metal, burned and melted varnish, and sizing, and the work done is defective, the metal being unevenly laid on, and the stamp presenting a ragged, unfinished appearance. In the second process four hands are required,

three of whom must be skilled operators, and while in it the die does not so quickly become clogged or stuffed as in the first process, it yet possesses the great disadvantage that a very small portion of the metal which is held by the sizing to the pencil constitutes the stamp, and it is difficult afterward to clean the pencil and remove the superfluous metal previous to the last varnishing or the boxing. Again, in the use of leaf metal, a great loss in material is experienced on account of its tearing so easily; and as in the second process the place for the stamp, or in the first process the face of the die itself, must be entirely covered with the leaf metal, any torn place in the leaf must be laid over again.

I have found that stamping with powdered bronze, if conducted properly, offers many and great advantages over the processes above named; but it is only after repeated and continued trials that I have discovered how to successfully apply bronze powder in order to produce these improved results. I have, for instance, attempted, in imitation of the ordinary process for printing paper with bronze, to print the stamp on the pencil with sizing, over which, when sufficiently dry, bronze powder was rubbed; but the result in this case was avery poor and perishable impression. Another process I attempted in imitation of the process first above named for leaf metal, was to stamp the uncovered pencil with a bronzed die; the result in this case was that the stamps were very unevenly bronzed and the dies quickly clogged. Another process, in imitation of the second process above named for leafmetal, was to lay the bronze powder on the pencil with some sizing, such as water, oil or other grease, glue, and gum solutions, 8270.; but in this case poor stamps were produced, the die was constantly clogged, and it Was almost impossible to clean the pencils on account of the tenacity with which the compound of bronze and sizing adhered to them. There was also great (lit'ficulty in handling the laid-on pencils. It was necessary to pass them from hand to hand while they were covered with bronze, and the operative who laid on the bronze could not work any faster than the one who stamped the pencils, because unless held in the hand they were liable to roll over, and the bronze surface would thus be destroyed and would have to be laid over again. I have also en deavored to apply the bronzeby stamping the uncovered pencil with a hot die, then quickly removing it from the press and rubbing bronze powder over the stamped portion. But the re salt in this case was bad stamps and clogged dies. The varnish would adhere to the face of the die and fill the pattern, and thereby a larger area was heated than desirable. The pencil would also cool very quickly, and consequently the bronze would only partly adhere to it.

Having thus indicated the difficulti eswhich attend thepractical application of bronze powder for the purpose of gilt-stampin g varnished surfaces, I shall now proceed to describe the process by which I have overcome the difficulties in the way of this application and have succeeded in economically producing a perfect stamp with bronze powder. My process is based upon the fact that I ap ply the powder to the varnished surface with out the interposition of any sizing, and then impress this bronze-coated, unsized, varnished surface with a die properly heated, which stamps the bronze in the pattern desired into the varnished surface, clean and perfect impression being thus produced, while the bronze powder is maintained in such condition that all of it, excepting that stamped in by the pattern-die, may be brushed off from the pencil without trouble, and so as to leave a clean-cut and )erfectly-defined stamp. I use a bronze powder which possesses sufficient adhesive power to adhere to the pencil without any sizin g. A very-finely ground and powdered bronze will be found to best answer this purpose. The machinery used is similar in arrangement to that employed in stamping with leaf metal. The process is as follows: The operative on the press dips the pencil in the bronze powder contained in the receptacle before him, gives one end of it a slight tap on the table to remove the superfluous powder, and then stamps the bronze-coated surface with a properly-heated die. As above stated, the powder should be of such nature as to adhere to and form a complete coat upon the varnished surface of the pencil without the use of an intermediate layer of sizing. When sizing is used, the powder soon fills up the fine lines of the die, whereby poor, indistinct, and bad-looking impressions are produced on the pencil, and much time is required in order to properly clean the die. The die should be moderately heated-far less than is required when leaf metal is used. I prefer to-employ a machine or press in which the die is heated by circulating water or other liquid, the head onto or into which the die is screwedbeing constructed in such manner that the temperature of the circulating liquid can be ascertained by a thermometer, whereby the heat can be exactly regulated to the required degree for the die. When the die is not warm enough the varnished surface of the pencil is not properly softened or melted to allow the bronze powder to be incorporated with and to adhere to the same, while if the die be too hot the varnish, being unduly melted, will penetrate through the bronze film or coat, and as a consequence of this a little of the varnish, together with some of the bronze powder, will adhere to the face of the die. During the continued use of the die this compound of melted varnish and powder gradually augments on the die, thereby dcstroyin g the sharpness and distinctness of the lines and ultimately cloggin g the die entirely. In the former case the stamp shows simply as an indentation on the pencil without bein g properly gilded; in the latter case it presents a smeared, uncleanly appearance, which may even make the pattern of the die entirely unrecognizable. (la-re must therefore be taken to properly regulate the temperature of the die, which can be done by means of the thermometer.

By this process only sufficient of the bronze powder adheres to the pencil to properly cover that part of the same to which the stamp is applied, and all the rest which drops off can be used over again, on account of the bronze being in a powdered condition, thereby effect ing a great saving in material. Besides the advantages hereinbefore stated as attending the process, I am enabled to reduce the number of operatives employed, as the person who attends to the stamping is also able to lay on thebronze. And again,thebronze adhering loosely to theupencil is cleaned off much more easily than the thin and tender leaf metal can be from the sized or greasy pencil, and as the bronze is of a fine grain-that is, reduced to almost an impalpable powder-it presents an even, unbroken surface on the pencil, thereby causing a cleaner and more perfect stamp to be produced. Another advantage in the use of bronze lies in the cheapness of the material and its adaptability to very fine and delicate work. The bronze powder is cheaper than metal leaf, which latter cannot be used where fine lines are desired, the only leaf used for that purpose being gold leaf; and even a gold leaf. will not make as clear and unbroken fine lines as the bronze powder. The gold leaf requires much skill in order to handle and apply it, and is seven times as expensive as bronze powder. The latter can, however, be used without trouble and without requiring great manipulative skill in all instances, includ ing fancy stamps, where the gold is now employed and further, it can be used in instances when the fineness of the lines would exclude the employment of even gold leaf. This process requires only two operativesone to lay on and stamp (the laying on requiring so little time that it can be performed during the reversion of the motion of the die in the press) and another to wipe and clean off the bronze after stamping. The latter operation requires no skill whatever, and the skill for the first one may be acquired easily in half a day, and all the operations may be performed by small girls or boys. The pencil, after being stamped and cleaned, can receive a thin coat of varnish the gilt finishing, so called-to protect the stamp from tarnishing,

I have described the process with special reference t0 the manufacture of Wooden lead-pencils; but it is also applicable to the stamping of other varnished surfaces.

What I claim, and desire to secure by Letters Patent, is

1. The process, herein described, of bronzestamping pencils and other varnished articles.

2. A lead-pencil bronze, stamped and then varnished, substantially as herein described, as an article of manufacture.

In testimony whereof I have signed my name to this specification before two subscribing witnesses.

, TEILE H. MULLER. Witnesses:

GEO. A. FREEMAN, 0. S. GRADY. (l1) 

